Analisi CFD in autoclave di sezioni di fusoliera 46-9 del velivolo B787

Report of Depart. of Aerospace Eng. of Pisa, DDIA 2009-23, Sept. 200

Flow around a wing: improvement of physical comprehension by using a DES model.

The flow around a wing is usually well represented by a RANS simulation in cruise conditions, because the zones with flow separations are absent or very small. But, as the angle of attack increases, because of the request of higher lift values, the separated flow zones become important, and the flow is more complex. In these conditions, a RANS approach, also with an unsteady solution, could be not satisfactory. Therefore, we decided to investigate this aspect, by comparing the results of an unsteady RANS solution with a DES solution. In the paper, the setting of both cases are described, as well as the comparison in terms of global coefficients, local distributions and field vorticity distributions. The results show that, at low angle of attack, not significant differences between the RANS and DES solutions occur. On the contrary, at higher angles of attack, the flow highlights a different behaviour (some results are shown in the following figures), with the DES approach that seems to give a more realistic representation of the flow itself. It is important to note that the difference between RANS and DES results is so considerable that also the lift, drag and pitching moment are significantly changed. Finally, it is possible conclude that the use of a DES approach appears an improvement to evaluate the aerodynamics characteristics of a wing close to the stall conditions, a relevant problem for the aerodynamics design of an airplane

Caratterizzazione delle prestazioni aerodinamiche del velivolo Selex Galileo Falco Evo

DDIA 2011-1

Centrifugal compressors Diffuser Rotating Stall Deep Insight

In this work the numerical analysis of a small flow coefficient stage vaneless diffuser is described. The main purpose of this analysis is to go inside the rotating stall physics with particular attention to the onset of the rotating cells and their properties. The diffuser aspect ratio (width divided radial extension) is low (0.03) and the effect of the wall (hub and shroud boundary layers) cannot be neglected. For this reason the model is a 3D model including the hub, the shroud walls and the downstream 180° cross- over bend. The numerical analysis has been carried out using an incompressible, viscous, unsteady commercial solver. Radial and tangential typical velocity profiles as produced by a hypotetical upstream impeller have been applied as boundary conditions and they have been changed in time to simulate the actual throttling valve closure as it is done during a test. Under these circumstances a rotating phenomenon is found to exist similar to what is found experimentally on similar geometries. The instability starts as a complex 3D flow involving both hub-to-shroud flow pulsations as well as radial non-uniformities and it stabilizes in the form of four rotating cells

Analisi del Flusso nei Condotti dei Radiatori per Diverse Geometrie di Imbocco

Report of Depart. of Aerospace Eng. of Pisa, DDIA 2005-10, Apr. 2005

Analisi CFD in autoclave di sezioni di fusoliera 46-8 nuova generazione del velivolo B787

Report of Depart. of Aerospace Eng. of Pisa, DDIA 2009-16, Sept. 2009

Analisi calda del flusso in autoclave

Report of Depart. of Aerospace Eng. of Pisa, DDIA 2009-22, Sept. 2009

Studio condotti dell’impianto di condizionamento del veicolo M139

Report of Depart. of Aerospace Eng. of Pisa, DDIA 2004-14, Aug. 200